Self-leveling mechanisms are known. For example, a variety of pendulum-type devices are currently being marketed light leveling. Many of these devices, however, are self-leveling in only a single direction. An example of such a device is shown in U.S. Pat. No. 7,031,367, which shows a housing with a pendulum pivotably connected to the housing. A first laser diode is disposed on the pendulum for emitting a first laser beam along a first path and a second laser diode disposed on the pendulum for emitting a second laser beam along a second patent that is substantially perpendicular and non-intersecting with respect to the first laser beam.
U.S. Pat. No. 5,539,990 shows an optical leveling, plumbing, and angle-calibrating device that uses a plumb body that has a ball received in a socket that is connected to a frame to provide a pendulous mount. Light sources are mounted above the ball to project a variety of lines, two of which are intersecting. While self-leveling mechanisms are useful for light leveling, it is also desirable to provide a mechanism for self-leveling for other uses.
Therefore, it is an object of the present invention to provide a self-leveling mechanism that is easy to use.